Abstract:

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Biaxial compression model tests on rockmass containing intermittent joints under plane
stress condition were carried out in this study, where the laser speckle photo technique was used for
measuring the displacement field. The results obtained have indicated that the laser speckle method
was effective and the measuring value was about 14% less than the measuring value of dial gauges.
Based on the displacement field and the principal stress field which were measured by laser speckle
photo technique, dial gauges and strain gauges, the angle of wing incipient crack, the evolution of
stress field at the joint tip and the path of crack extension were deeply studied. The deformation and
failure characteristics, including the fracture mechanism of rockmass, were also analyzed in this
study.

Abstract: A complete stress-strain experiment curve, gained through exerting low confining pressure
on brittle rock, reflects the deformation and destruction process of rock under different confining
pressure, and reveals that after the destruction of rock, not only slip deformation but also
re-destruction process will take place, which would possibly lead to further reduction of the
mechanical properties of the rock mass. Through the analysis of the relation between complex failure
modes, load carrying capacity after rock destruction and the volumetric strain, the paper gives us a
further explanation of the complex destructive process of rock. The basis for the rock’s load-carrying
capacity after destruction is an effective restraint stress, which shows that effective supporting in
underground engineering is the key factor for providing the cracked surrounding rock with
load-carrying capacity and guaranteeing the stability of the structure.

Abstract: In this article, through the seismic experimental analysis for six frame joints of ultra-high toughness cementitious composites, the load-carrying capacity, hysteretic behavior, energy dissipation and ductility of new joints are studied under different axial compressive ratio and the stirrups space. The experimental results show that the UHTCC joints have higher anti-cracking capacity and shear ductility. The UHTCC can reduce or even eliminate the amount of shear stirrups of the joint core. According to the analysis for the experiments, a theoretical calculating formula of shearing capacity is presented, whose calculating results agree well with the experimental results.

Abstract: This paper uses ANSYS finite element program to do the nonlinear finite element analysis on steel reinforced concrete L-shaped short-shear walls. Through applying the vertical and horizontal load on the model, three typical stages of the whole working period are studied. And the cracking load and deformation regularity in various stages are obtained. The development process of cracks until the specimen damaged is revealed. At last, the development process of crack distribution at different stages is studied.

Abstract: Pile foundation design has gradually used the super-long pile structure form with the port and offshore engineering construction developing towards to the direction of large-scale, deepwater, and coast geological becomes more complex, bearing stratum becomes more deeper. PHC pile is the first choice of pile foundation design form, just because it has many advantages. The former researches of pile vertical load mainly on limit bearing capacity, the calculation is reasonable for short pile and middle long pile, however, it is not reasonable for super-long pile, pile body side and tip resistance can not reach the limit when structure is to limit. This paper puts forward the calculation model of super-long PHC pile vertical load in soft clay based on vertical load mechanism analysis and experimental research on the foundation pile, and the calculated and test value coincide preferably.